At the end of the post you can vote for the right diagnosis! 

Click on the option that you think is correct and then click on the “Get Results” button to see if you’ve succeeded.

A nodular lesion with a granulomatous aspect is observed in the lung of a sheep’s carcass.

Sheep lung. Sectioned granulomatous lesion, encapsulated, with a caseous appearance, with concentric lamellations (onion like) and greenish colouration.


What is your diagnosis? (76)


The microbiological culture allowed isolating a pure Corynebacterium pseudotuberculosis culture from the lesion. It is therefore a case of Caseous lymphadenitis. Although it is a bacterial piogranulomatous pneumonia, the disease is known as caseous lymphadenitis because it usually affects the lymph nodes. The most common pathogenesis is that the bacterium enters through skin wounds (during  shearing, for example) and, through the lymphatic vessels, accesses the lymph nodes where the primary lesion occurs, from there spreads via hematogenous or lymphatic to other viscera, in this case the lungs, but there may also be other entry routes (respiratory, oral ...). In sheep it is usually observed in pre-escapular or precrural lymphatic nodules. The distribution in concentric layers is typical of this microorganism due to its soluble exotoxin, the organism tries to encapsulate the lesion but the abscess continues to grow concentrically. Greenish coloration is due to the presence of eosinophilic polymorphonucleated leukocytes in the inflammatory exudate, which also contains macrophages and neutrophils.
Your answers are highlighted below.
Question 1
What is your diagnosis?
Caseous penumonia (Corynebacterium pseudotuberculosis)
Abscessing pneumonia (Trueperella pyogenes)
Granulomatous pneumonia (Mycobacterium caprae)
Caseous lymphadenitis (Corynebacterium pseudotuberculosis)
Melioidosis (Burkholderia pseudomallei)
Once you are finished, click the button below. Any items you have not completed will be marked incorrect. Get Results
There is 1 question to complete.